1. Technical Field
The present invention relates to a cooling system including a circulation path in which a coolant for cooling a heat source in a system circulates, and a reservoir unit and a cartridge used in the cooling system. The present invention also relates to a solid-state laser oscillator system provided with the cooling system.
2. Background Art
In the case of solid-state lasers, visible light or near-visible light is emitted from a flashlamp serving as an optical pumping source, and this optical energy is stored in a laser rod and converted into a laser beam. However, the energy conversion efficiency of this case is low, and most of the optical energy from the flashlamp is converted into heat. At this time, the energy efficiency in the laser rod decreases along with increase of the temperature.
In order address this problem, solid-state lasers usually include a cooling system for cooling the laser rod (see, for example, Japanese Unexamined Patent Publication No. 2002-198593 (hereinafter, Patent Document 1)). As shown in FIG. 14, for example, this type of cooling system is formed by a circulation path 85 that includes a resonator 80 (or a laser chamber) including a laser rod, which is the heat source, a heat radiator 81, a reservoir tank 82, a pump 83 and a filter 84. In the circulation path 85, a coolant fed from the reservoir tank 82 by the pump 83 passes through the filter 84, where foreign matters are removed from the coolant, and then the coolant is brought into direct contact with the laser rod in the resonator 80 to absorb heat generated at the laser rod. The heat absorbed by the coolant is radiated at the heat radiator 81, and then the coolant is returned to the reservoir tank 82. The coolant circulates in the circulation path such that the above-described steps are repeated.
The coolant is gradually contaminated due to water stain, etc., as the coolant repeatedly circulates in the circulation path, and therefore the coolant is replaced on a regular basis. Conventionally, this replacement work of the coolant is achieved by removing the coolant from the reservoir tank with a dropper, or the like, and then replenishing the reservoir tank with fresh coolant.